KR970003811Y1 - Twin screw of a ship - Google Patents

Abstract

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Description

Ship propulsion system

The present invention relates to a propulsion device of a ship, and more particularly, to improve their installation position by providing a pair of left and right propellers to improve the propulsion performance of the ship.

(Prior Art)

There is a technology provided with two propellers (propulsion) to improve the propulsion performance of the ship. If two propellers are provided, the load per propeller is halved, and the propeller efficiency is improved. In this case, it is important to prevent the increase of resistance and to reduce the hull effectiveness, and as a conventional technique capable of realizing this, a double inverted propeller or an overlapping propeller is known. (E.g. Japanese Utility Model Open Fire No. 58-149291)

The overlapping propellers are installed by shifting the front and rear positions of the two propellers so as to close the shaft spacing so that the rotation surfaces of the propellers overlap when viewed from the rear. In addition, an interlocking propeller is proposed in which the two propellers are rotated in the same plane as further development of the overlapping propeller (see, for example, Japanese Utility Model Publication No. 60-103095). ).

However, the interlocking propeller of the above publication is limited to a small number of wings or small area propellers, or the propeller shaft center distance is increased, resulting in a decrease in hull efficiency. In other words, bilge vortices V1 and V2 symmetrically generated in the left and right strings exist in the flow into the propeller installed at the stern in general. Since these bilge vortices V1 and V2 are accompanied by rotational flows (inward rotational flows) directed to the hull centerline around them, the hull efficiency is greatly changed under the influence of the bilge vortex of the hull in relation to the position of the propeller and the direction of rotation.

In order to improve the propulsion efficiency by utilizing the bilge vortex of the hull, in the technique described in Japanese Patent Laid-Open No. 63-34294, one propeller is installed by shifting the shaft center from the hull centerline to the post or the left side. The advantage of the interlocking propeller, which is originally formed by two propellers (reduced propeller load, improved propeller efficiency, etc.) is not obtained, and only one bilge vortex can be used by one propeller, so that a great improvement in hull efficiency can be expected. It is disadvantageous to design and manufacture of the hull structure due to the unbalanced center of gravity, and also to the ships' keeping and shipbuilding properties.

Therefore, the inventors of the present application have shown that two propeller centers are used to effectively improve propulsion efficiency by effectively using the right and left bilge vortex as shown in Japanese Utility Model Publication No. Hei 2-68296. Two propellers, each positioned near the center of the left and right bilge vortices, have interlocking propellers formed by forming rakes of the propeller blades in different directions, and both propellers are directly opposite to the bilge vortex. A propulsion device for a ship is proposed to be driven outward synchronously.

In the conventional overlapping propellers, the left and right pairs of propellers are installed to be largely out of position in the front and rear directions compared to the interlocking propellers, resulting in an imbalance of propeller propulsion of the left and right pairs, which is disadvantageous in terms of ship supplementation and shipbuilding, and both propellers. To solve the imbalance of propulsion of the

Such technically difficult measures are necessary.

Furthermore, since the rake of both propellers is inclined in the same direction, there is a limit in reducing the imbalance force by reducing the front and rear spacing of both propellers.

In the interlocking propeller of Japanese Patent Application Laid-Open No. 2-68296, in the case of synchronous rotational driving with two propellers in one cycle, the propeller shaft system is complicated or synchronous rotational driving as two cycles. In this case, there is a problem that the cycle control device becomes complicated and propellers are easily damaged by blowing off the sea floating material between the two propellers.

It is an object of the present invention to provide a propulsion device for a ship that can effectively utilize propulsion bilge vortex on the left and right, and that the propeller shaft system and the cycle control device do not complicate.

(Means to solve the task)

In the ship propulsion device according to claim 1, a pair of right and left propellers are installed at the same height, and the height direction position of both propellers and the width direction position of the hull are located near the center of the bilge vortex at the center of both propellers. The propellers are set to be positioned respectively, and the rotational direction of both propellers is set to rotate in the opposite direction to the bilge vortex, that is, outward. In the plan view, the rear propeller is arranged in the longitudinal direction of the hull so as not to overlap each other so as to be the front propeller and the rear propeller, and the rear propeller can recover the rotational flow energy generated from the front propeller by the rear propeller. The amount of deviation is 0 .05Dp If Dp is 0.15 to recover the bilge vortex and the propeller wake energy of the rotational flow at the same time to obtain a larger driving force as a whole by arranging to the extent of (Dp is the diameter of the propeller).

1 is a schematic rear view of a ship propulsion system

2 is a schematic plan view of a ship propulsion system

3 is the layout of the reflux distribution and propeller

4 is a schematic layout of propellers and cycles

5 is a diagram of propeller shaft spacing and horsepower characteristics.

6 is a comparison of the horsepower curve of the present invention and the conventional uniaxial ship

* Explanation of symbols for main parts of the drawings

1, 2: propeller 1A, 2A: propeller boss

1B, 2B: Propeller Shaft V1, V2: Bilge Swirl

In the ship propulsion device according to claim 1, a pair of left and right propellers are installed at the same height position, and the height direction position of both propellers and the width direction position of the hull are such that the centers of both propellers are close to the center of the bilge vortex at the left and right sides. Each of the propellers is set to be positioned at each other, and the rotational direction of the propellers is set to rotate in the opposite direction to the bilge vortex, that is, outwardly.

Both propellers are located at the position displaced back and forth in the longitudinal direction of the hull, so that the propeller rotation surfaces are located close to each other without overlapping each other in plan view, and their rakes are formed to be inclined in opposite directions to each other away from the other propellers. Therefore, the front and rear spacing of both propellers is very small, so that the imbalance generated due to the different positions before and after the propellers can be minimized.

In addition, since both propellers are installed so that they do not interfere with each other, the propeller shaft system does not need to be rotated synchronously, so the propeller shaft system is not complicated or the cycle control device is complicated. It is difficult to cause damage.

In the ship propulsion device according to claim 2, the propeller center of both propellers is set in the range of 0.5p to 0.75Dp above the ship's baseline, and the spacing between the centers of both propellers is (0.5b + 0.5Dp) to 0.75. It is set in the range of Dp, and the shift | offset | difference amount of the said ship propeller in the longitudinal direction of the hull is set to 0.05Dp-0.15Dp.

The range of 0.5Dp to 0.75Dp above the baseline of the hull is set based on the height position of the center of the symmetrical bilge vortex, and (0.5b + 0.5Dp) is that one propeller tip interferes with the other propeller boss The 0.7 Dp is set based on the width direction of the hull of the bilge vortex, and the 0.05 Dp to 0.1 15 Dp adds the width in the longitudinal direction of the hull of the rake and the propeller facing each other. It is set.

By setting the height position of both propellers and the spacing between the propeller centers as described above, the centers of both propellers can be matched to each other near the center of the bilge vortex on the left and right, and the rakes of both propellers are opposite to each other so as to move away from the other propellers. The front and rear spacing of both propellers can be made very small by setting the space | interval in the ship body direction as mentioned above, and setting it as mentioned above.

As described in the above operation, the following effects are obtained.

According to the ship propulsion device according to the claims, the centers of a pair of left and right propellers are positioned near the centers of the left and right bilge vortices, respectively, and the rotational direction of both propellers is set in the opposite direction to the bilge vortex to effectively make the left and right bilge vortices. It can be used to improve hull efficiency.

Both propellers are formed by varying the hull longitudinal positions of both propellers and by bringing the rakes of both propellers in opposite directions in a direction away from the other propellers, as long as their rotational surfaces do not overlap with each other in a plane view. By reducing the front and rear spacing of, the unbalance caused by the different propellers' front and back positions can be minimized.

In addition, since both propellers do not need to be rotated synchronously, the propeller shaft system is not complicated or the cycle control device is complicated, and the number of propeller blades is not limited.

In addition, by setting the height positions of the propellers and the spacing between the propeller centers as described above, the centers of both propellers can be matched to the centers of the bilge swirls on the left and right, respectively, and the rakes of both propellers are opposite to each other so as to be far from the other propellers. The front and rear spacing of both propellers can be made extremely small by making it face to the direction and setting the space | interval of the hull longitudinal direction of both propellers as mentioned above.

Next, embodiments of the present invention will be described with reference to the drawings.

(Example)

This embodiment is an embodiment when the present invention is applied to a propulsion device installed on the stern of the tanker (tanker), Figure 1 is a rear view of the propulsion device from the rear of the hull, Figure 2 is a schematic plan view of the propulsion device. .

In these figures, two (one pair of left and right) propellers 1, 2 (where 1 represents starboard and 2 represents port) are symmetrical to the hull centerline C, and furthermore, the propeller axes lB, 2B. It is installed in parallel.

The position in the height direction of the propellers 1 and 2 and the width direction of the hull are located near the center of the bilge vortex V1, V2 (see FIG. 3) of the shafts lB and 2B of both propellers 1.2. The propellers 1 and 2 are set to be positioned respectively, and the rotational direction of both propellers 1 and 2 is set in the opposite direction to the bilge vortex V1 and V2, i.e., around the outer periphery, and both propellers 1 and 2 are in the position shifted back and forth in the hull length direction. The propeller rotating surfaces are installed in close proximity to each other within the extent that they do not overlap with each other in plan view, and both propellers 1 and 2 are inclined in opposite directions to each other in a direction away from the propellers 1 and 2 of the opponent. Formed.

In the illustrated case, the rake of the starboard propeller 1 is formed to be inclined rearward in a plane orthogonal to the propeller 1, 2 axis lB, and the rake of the port propeller 2 on the propeller shaft 2B. It is formed to incline forward at the orthogonal surface.

In FIG. 1, the dotted line shows the hull line diagram of the stern part, and the linear line shown in this figure is formed symmetrically with respect to the hull centerline C, and is called uniaxial linear shape which gradually becomes narrow as it moves to the stern end. Hull. S is a stern and 3 is a rudder provided in the back of the propellers 1 and 2. As shown in FIG.

In such uniaxial flow, bilge vortices V1 and V2 of left and right symmetry exist as shown in the water flow distribution and propeller arrangement of FIG. 3.

Arrows in the figure show the direction of the water flow of the bilge vortex V1, V2, and the dotted line indicates the current flow with the same flow rate. The bilge uses V1 and V2 to form an inward rotation (counterclockwise rotation in the starboard or clockwise rotation in the port) from the hull center.

From there, propeller shafts (1B and 2B) are placed near the center of this bilge vortex V1 and V2 so that the propeller rotational directions Rl and R2 rotate outwards in the opposite directions to the bilge vortex V1 and V2.

As a result, the effective use of the bilge vortex V1 and V2 of the left and starboard is achieved, and the hull efficiency can be improved. In addition, in FIG. 3, the code | symbol 1C, 2C shows the outer periphery of the rotational trajectory of the starboard propeller 1 and the port propeller 2, respectively. Reference numerals 9 and 9C respectively refer to the outer periphery of the propeller shaft and the rotational trajectory of the propeller on one axis line. Reference numerals 1A and 2A denote bosses of the propellers 1 and 2, respectively.

4 shows the installation of the propellers 1 and 2 and the cycle 4, in the case of the present embodiment, both propellers 1 and 2 are driven independently by two identical cycles 4 of the same type. The output shaft of only one period may be connected to both propellers 1 and 2 via a gearbox to drive. The propeller shafts 1B and 2B may be inclined with each other in an enlarged shape slightly rearward in the same plane.

As a result of extensive water tank tests on the propulsion system according to the present invention, the most suitable height position of the two propellers (1, 2) is 0.75Dp or less above the hull baseline (where Dp is the propeller diameter), and The distance between the propeller shafts lB and 2B of the two propellers 1 and 2 ranged from (0.5b + 0.5Dp) to 0.75Dp or less (where b is the diameter of the propeller boss). .

The height positions 0.5Dp to 0.75Dp are necessary to position the center of the propellers 1 and 2 near the centers of the bilge vortices V1 and V2, and also the lower limit of the spacing between the propeller axes lB and 2B (0.5b + 0.5). Dp) is set so that the tip of one propeller 1, 2 does not interfere with the bosses 1A, 2A of the other propellers 1, 2, and the upper limit 0.7Dp is the center of the propeller 1, 2. Is needed to place the vortex near the center of the vortex V1, V2.

In addition, in order to minimize the imbalance of the propulsion force of the left and right propellers (1. 2), it is preferable to set the front and rear spacing of both propellers (1, 2) very little, and for this purpose, the propellers (1, 2) have their rakes. Is inclined in a direction away from the propellers 1 and 2 of the other side, and the propellers 1 and 2 are made by adding the rake (but the size thereof is a normal value) and the front and rear widths of the propellers 1 and 2. The shifted amount in the hull longitudinal direction is set to 0.05 Dp to 0.15 Dp.

In FIG. 5, the vertical axis shows the propulsion horsepower of the present invention and the propulsion horsepower of the normal uniaxial ship, and the horizontal axis shows the ratio between the propeller shaft diameters BB and 2B in the hull width direction and the propeller diameter Dp. According to it, when propeller shaft space | interval is 0.75Dp or less, it turns out that propulsion horsepower Hp decreases compared with normal one-axis line.

In addition, as shown in the comparison of the horsepower curve of FIG. 6, it is found that a horsepower reduction effect of about 15% is obtained in the full load state and the ballast state as compared with the normal uniaxial line. In the figure, the vertical axis represents propulsion horsepower, and the horizontal axis represents ship speed. However, the dotted line is the case of the normal uniaxial line, and the solid line represents the case of the present invention.

In the above-described propulsion system of a ship, a pair of left and right propellers 1 and 2 are installed at the same height, and the height direction position and the hull width direction position of both propellers 1 and 2 are both propellers 1. 2) the center of gravity is set so as to be located near the centers of the left and right bilge vortex V1 and V2, respectively, and the rotational direction of both propellers 1.2 is set to be opposite to the bilge vortex V1 and V2, i.e. outward rotation. Bilge Vortex V1 and V2 can be effectively used to improve hull efficiency. ++++++++

Both propellers 1 and 2 are located at positions different from the longitudinal direction of the hull so that their rotational surfaces are located close to each other within the extent that they do not overlap with each other in plan view, and both propellers 1 and 2 are It is formed so as to be inclined in opposite directions in a direction away from the propellers 1 and 2 of the other side, so that the front and rear positions of both propellers 1 and 2 are made very small, and the front and rear positions of the propellers 1 and 2 are different. Imbalance can be minimized.

In addition, since both propellers 1 and 2 are installed so as not to interfere with each other, there is no need to rotate both propellers 1 and 2 synchronously, so that the propeller shaft system is not complicated or the cycle control device is complicated. The restriction is also eliminated, and damage to the propeller caused by the seafloat is unlikely to occur.

In addition, the starboard propeller 1 may be provided in front of the port propeller 2, or each blade of the starboard propeller 1 may be set between the respective blades of the port propeller 2 so that both propellers 1, 2 It is also preferable to drive rotation synchronously.

In addition, the present invention is obvious that the ship propulsion device is not limited to tankers can be applied to various vessels.

Claims (1)

Install a pair of jaw propellers at the same height, The height position and the hull width position of both propellers are set so that the centers of both propellers are located near the centers of the bilge vortex on the left and right, respectively. The direction of rotation of both propellers is set to rotate opposite to the bilge vortex, i.e. outward, Both propellers are provided in the propulsion system of ships formed such that their rakes are inclined in opposite directions to each other away from the other propellers. The left and right propellers are arranged to be shifted back and forth in the longitudinal direction of the hull so that the rotation surfaces of these propellers do not overlap with each other in a plan view so as to be the front propeller and the rear propeller, and to recover the downstream rotational energy generated from the front propeller by the rear propeller. A ship characterized in that the amount of deviation in the longitudinal direction of the hull is installed close to the range of 0.05 Dp to 0.15 Dp (Dp is the propeller diameter) to simultaneously recover the bilge vortex and the rotary flow energy of the propeller wake to obtain a greater propulsion force as a whole. Propulsion unit.